Pit Zips Good or Hype ?

John, in my experience, pit zips are great for dumping heat without exposing inner layers to precipitation. No fabric can breathe as well as a protected vent, (yes, I've owned Epic). The additional weight is worth the additional comfort IMO.

I have found pitzips are extremely useful for dumping heat. When there is a good breeze, they can also be very effective at moving moisture. Is a wpb jacket + pitzips as breathable as some ultra breathable dwr windshirt? Nope. But when the rain is coming down hard, it will keep me drier.

When I compared an early eVENT jacket without pitzips to a Montbell Peak with pitzips, I found that the eVENT jacket breathed better, but the pitzips of the Peak made up for the lack of breathability everywhere but my fore-arms. I think there are lighter eVENT fabrics now, so it might be a draw… but I hope I have several years of life left in my Montbell Peak, so I haven't tried any of the newer eVENT jackets.

–mark

When I run, I find a light waterproof (HyVent, Goretex, Event, etc.) with chest unzipped a bit, pit zips open and hem loosened provides about the same or better breathability than a windshirt without pit zips. The pit zips allow good airflow from the chest or hem.

Might be worthwhile to check out the OR Celestial Jacket. Rather than pit zips, it has separable torso zippers; these allow you to open the jacket at the sides and even wear the front of the jacket over your hipbelt rather than under. Lots of ventilation, and it's recently updated to a heavier version, so you can probably find a great deal right now.

Gotta have 'em with Epic and Gore-Tex. I've just bought an eVENT shell without pit zips to see if there really is a fabric that's breathable enough so that I don't need them when wearing a pack. My experience with eVENT has been very favorable but I won't be surprised if I have to add the zippers.Check back in few months for field results!

whatever vent you open it works much better if there is no windshirt and little or no insulation underneath. A pit zip with a pertex and down jacket under would not work well. An open pit zip with a short sleeve shirt and a sleevless down gilet would. With a front zip rain jacket I try to wear all layers under with front zips too